<html>
<head>
	<meta charset="UTF-8">
	<meta content="IE=edge" http-equiv="X-UA-Compatible">
	<meta content="initial-scale=1.0, maximum-scale=1.0, user-scalable=no, width=device-width" name="viewport">
	<title>2563：阿狸和桃子的游戏</title>
	<!-- css -->
	<link href="../css/base.min.css" rel="stylesheet">
	<link href="../css/project.min.css" rel="stylesheet">
	
	<!-- favicon -->
	<!-- ... -->
</head>
<body class="page-brand">
	<header class="header header-transparent header-waterfall ui-header">
		<ul class="nav nav-list pull-left">
			<li>
				<a data-toggle="menu" href="#menu">
					<span class="icon icon-lg">menu</span>
				</a>
			</li>
		</ul>
		<a class="header-logo header-affix-hide margin-left-no margin-right-no" data-offset-top="213" data-spy="affix">阿狸和桃子的游戏</a>
		<span class="header-logo header-affix margin-left-no margin-right-no" data-offset-top="213" data-spy="affix">阿狸和桃子的游戏</span>
	</header>
	<nav aria-hidden="true" class="menu" id="menu" tabindex="-1">
		<div class="menu-scroll">
			<div class="menu-content">
				<a class="menu-logo" href="../index.html">BZOJ离线题库</a>
				<ul class="nav">
					<li>
						<a class="waves-attach" data-toggle="collapse" href="#problems">题目</a>
						<ul class="menu-collapse collapse in" id="problems">
							<li>
								<a class="waves-attach" href="../index.html">主页</a>
							</li>
							<li>
								<a class="waves-attach" href="../list.html">题目列表</a>
							</li>
						</ul>
					</li>
					<li>
						<a class="collapsed waves-attach" data-toggle="collapse" href="#about">关于</a>
						<ul class="menu-collapse collapse" id="about">
							<li>
								<a class="waves-attach" href="../about.html">关于此项目</a>
							</li>
						</ul>
					</li>
					
				</ul>
			</div>
		</div>
	</nav>
	<main class="content">
		<div class="content-header ui-content-header">
			<div class="container">
				<h1 class="content-heading">
                阿狸和桃子的游戏                </h1>
                <p>时间限制：3s&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;  空间限制：128MB</p>			</div>
		</div>
		<div class="container">
			<section class="content-inner margin-top-no">
				<div class="row">
					<div class="col-lg-13 col-md-13">
						<div class="card margin-bottom-no">
							<div class="card-main">
								<div class="card-inner">
									
                                <h3>题目描述</h3><p><div style="background: white" align="left"><span style="font-size: 12pt; color: #200000">　　阿狸和桃子正在玩一个游戏，游戏是在一个带权图</span><span style="font-size: 12pt; color: #200000">G=(V, E)</span><span style="font-size: 12pt; color: #200000">上进行的，设节点权值为</span><span style="font-size: 12pt; color: #200000">w(v)</span><span style="font-size: 12pt; color: #200000">，边权为</span><span style="font-size: 12pt; color: #200000">c(e)</span><span style="font-size: 12pt; color: #200000">。游戏规则是这样的：</span><span style="font-size: 12pt; color: #200000"><br />
</span><span style="font-size: 12pt; color: #200000">　　</span><span style="font-size: 12pt; color: #200000">1. </span><span style="font-size: 12pt; color: #200000">阿狸和桃子轮流将图中的顶点染色，阿狸会将顶点染成红色，桃子会将顶点染成粉色。已经被染过色的点不能再染了，而且每一轮都必须给一个且仅一个顶点染色。</span><span style="font-size: 12pt; color: #200000"><br />
</span><span style="font-size: 12pt; color: #200000">　　</span><span style="font-size: 12pt; color: #200000">2. </span><span style="font-size: 12pt; color: #200000">为了保证公平性，节点的个数</span><span style="font-size: 12pt; color: #200000">N</span><span style="font-size: 12pt; color: #200000">为偶数。</span><span style="font-size: 12pt; color: #200000"><br />
</span><span style="font-size: 12pt; color: #200000">　　</span><span style="font-size: 12pt; color: #200000">3. </span><span style="font-size: 12pt; color: #200000">经过</span><span style="font-size: 12pt; color: #200000">N/2</span><span style="font-size: 12pt; color: #200000">轮游戏之后，两人都得到了一个顶点集合。对于顶点集合</span><span style="font-size: 12pt; color: #200000">S</span><span style="font-size: 12pt; color: #200000">，得分计算方式为<img height="71" width="266" alt="" src="../file/2563_0.jpg" /></span><span style="font-size: 12pt; color: #200000"><br />
</span><span style="font-size: 12pt; color: #200000">　　</span><span style="font-size: 12pt; color: #200000">。</span><span style="font-size: 12pt; color: #200000"><br />
</span><span style="font-size: 12pt; color: #200000">　　由于阿狸石头剪子布输给了桃子，所以桃子先染色。两人都想要使自己的分数比对方多，且多得越多越好。如果两人都是采用最优策略的，求最终桃子的分数减去阿狸的分数。</span></div>
<div style="background: white" align="left"><span style="font-size: 12pt; color: #200000">　</span></div></p><hr/><h3>输入格式</h3><p><p><font size="3"><font color="#200000">　输入第一行包含两个正整数<span style="font-size: 12pt; color: #200000">N</span></font></font><span style="font-size: 12pt; color: #200000">和</span><span style="font-size: 12pt; color: #200000">M</span><span style="font-size: 12pt; color: #200000">，分别表示图</span><span style="font-size: 12pt; color: #200000">G</span><span style="font-size: 12pt; color: #200000">的节点数和边数，保证</span><span style="font-size: 12pt; color: #200000">N</span><span style="font-size: 12pt; color: #200000">一定是偶数。</span><span style="font-size: 12pt; color: #200000"><br />
</span><span style="font-size: 12pt; color: #200000">　　接下来</span><span style="font-size: 12pt; color: #200000">N+M</span><span style="font-size: 12pt; color: #200000">行。</span><span style="font-size: 12pt; color: #200000"><br />
</span><span style="font-size: 12pt; color: #200000">　　前</span><span style="font-size: 12pt; color: #200000">N</span><span style="font-size: 12pt; color: #200000">行，每行一个整数</span><span style="font-size: 12pt; color: #200000">w</span><span style="font-size: 12pt; color: #200000">，其中第</span><span style="font-size: 12pt; color: #200000">k</span><span style="font-size: 12pt; color: #200000">行为节点</span><span style="font-size: 12pt; color: #200000">k</span><span style="font-size: 12pt; color: #200000">的权值。</span><span style="font-size: 12pt; color: #200000"><br />
</span><span style="font-size: 12pt; color: #200000">　　后</span><span style="font-size: 12pt; color: #200000">M</span><span style="font-size: 12pt; color: #200000">行，每行三个用空格隔开的整数</span><span style="font-size: 12pt; color: #200000">a b c</span><span style="font-size: 12pt; color: #200000">，表示一条连接节点</span><span style="font-size: 12pt; color: #200000">a</span><span style="font-size: 12pt; color: #200000">和节点</span><span style="font-size: 12pt; color: #200000">b</span><span style="font-size: 12pt; color: #200000">的边，权值为</span><span style="font-size: 12pt; color: #200000">c</span><span style="font-size: 12pt; color: #200000">。</span></p>
<div style="background: white" align="left"><span style="font-size: 12pt; color: #200000">　</span></div></p><hr/><h3>输出格式</h3><p><p><font color="#200000" size="3">　输出仅包含一个整数，为桃子的得分减去阿狸的得分。</font></p></p><hr/><h3>样例输入</h3><pre>4 4
6
4
-1
-2
1 2 1
2 3 6
3 4 3
1 4 5
</pre><hr/><h3>样例输出</h3><pre>3
数据规模和约定
　　对于40%的数据，1 ≤ N ≤ 16。
　　对于100%的数据，1 ≤ N ≤ 10000，1 ≤ M ≤ 100000，-10000 ≤ w , c ≤ 10000。
 </pre><hr/><h3>提示</h3><p>没有写明提示</p><hr/><h3>题目来源</h3><p>2012国家集训队Round 1 day2</p>
								</div>
							</div>
						</div>
					</div>
				</div>
				
				
			</section>
		</div>
	</main>

	<div class="fbtn-container">
		<div class="fbtn-inner">
			<a class="fbtn fbtn-lg fbtn-brand-accent waves-attach waves-circle waves-light waves-effect" data-toggle="dropdown" aria-expanded="true"><span class="fbtn-text fbtn-text-left">Menu</span><span class="fbtn-ori icon">apps</span><span class="fbtn-sub icon">close</span></a>
			<div class="fbtn-dropup">
				<a class="fbtn fbtn-brand waves-attach waves-circle waves-light waves-effect" href="../list.html" target="_self"><span class="fbtn-text fbtn-text-left">题目列表</span><span class="icon">menu</span></a>
				<a class="fbtn fbtn-green waves-attach waves-circle waves-effect" href="../index.html" target="_self"><span class="fbtn-text fbtn-text-left">返回主页</span><span class="icon">home</span></a>
				<a class="fbtn waves-attach waves-circle waves-effect" href="http://www.lydsy.com/JudgeOnline/submitpage.php?id=2563" target="_blank"><span class="fbtn-text fbtn-text-left">提交代码</span><span class="icon">send</span></a>
				<a class="fbtn fbtn-orange waves-attach waves-circle waves-effect" href="http://www.lydsy.com/JudgeOnline/wttl/wttl.php?pid=2563" target="_blank"><span class="fbtn-text fbtn-text-left">试题讨论</span><span class="icon">chat</span></a>
				
			</div>
		</div>
	</div>

	<!-- js -->
	<script src="../js/jquery.min.js"></script>
	<script src="../js/base.min.js"></script>
	<script src="../js/project.min.js"></script>
</body>
</html>